NYL-2000DExperimental platform for flow conductivity of type cracks

1Purpose and significance of the experiment

2、 Basic Principles of Instruments

The crack flow meter is developed according to API standards. It can simulate downhole pressure and temperature under standard experimental conditions to evaluate the conductivity of fracture proppants to different fracturing fluids, and thus compare the performance of various proppants fracturing fluids. The testing method is as follows:

1Apply different closing pressures to the testing chamber containing proppant using a hydraulic press to make the proppant in a semi stable state.

2Inject test fluid into the proppant layer, collect data through various sensors and computers at regular intervals, and measure the crack width, pressure difference, etc. under each closing pressure.

3Calculate the permeability and fracture conductivity of the proppant layer using Darcy's formula, and evaluate the damage caused by fracturing fluid to the conductivity.

4Repeat this process until all required closure pressures and flow rates are evaluated.

5Heat the testing room to the temperature of the coal deposit and then test the proppant layer.

3、 Instrument system process

This instrument consists of the following components:

1A linear flow guide chamber (radial flow guide chamber) that meets API standards, with a test area of 64.5 cm²The upper and lower ends of the proppant can be equipped with rock molds and disassembly tools.

2Hydraulic press and pressure compensation system;

3Linear displacement sensor;

4. Experimental liquid displacement system, including displacement pump and pulse pressure damper, etc;

5. Differential pressure gauge, pressure sensor;

6Backpressure regulation system;

7. Balance;

8Heating and temperature control system;

9Vacuum system;

10Automatic control system;

4、 Main technical indicators

1Liquid flow rate range: 0-20mL/min;

2Test pressure: maximum 10MPa;

3Operating temperature: room temperature~200 ℃, accuracy: ± 1 ℃;

4Closing pressure: 0-120MPa;

5Proppant thickness: 0.25-1.27cm;

6Liquid pressure difference: ΔP(0－10Kpa)、 Accuracy 0.25% F.S;

7Flow capacity: 0-1200 μ m²_·cm；

8Penetration rate: 0-2000 μ m²；

9Displacement: ± 20mm, accuracy: 0.003mm;

10Working fluids: oil, water, fracturing fluid, etc.

5、 Overview of the various systems that make up the instrument

5.1 constant flux pump

Flow regulation range: 0.01~20ml/min, working pressure: 6000PSI, accuracy:<± 1%, working voltage: 220V ± 10%, 50Hz ± 2Hz, power consumption: 75W.

The pump is equipped with pressure measurement and overvoltage/undervoltage protection systems, ensuring safe and reliable operation of the pump system. The working parameter setting adopts keyboard input, touch button operation, with four digit data display, intuitive and convenient operation.

5.2 preheater

In the experiment requiring heating, in order to ensure that the experiment is carried out at the required temperature, the injected fluid needs to be preheated to ensure that the temperature of the injected fluid and the guide chamber is maintained. The preheating power of the preheater is 500W, and the temperature control range is from room temperature to 180 ℃.

5.3 Diversion chamber

The guiding chamber used in the instrument is strictly produced according to the linear flow guiding chamber specified in the API standard. The thickness of the supporting agent filling layer is adjustable from 0.25 to 1.27cm, and the testing area is 64.5cm²， The maximum load capacity is 1200KN, with a working temperature of 180 ℃ and an internal maximum pressure of 10MPa. The upper and lower pistons, metal plates, and flow chambers are all made of high-strength stainless steel materials, which have a certain degree of corrosion resistance and high pressure resistance, ensuring that no plastic deformation occurs under test pressure. The flow chamber filter screen is made of stainless steel metal powder, with a thickness of 3mm and a retained particle size of less than 65 μ m.

5.4 differential pressure sensor

Select DP1300-A-C-2-S₂The differential pressure transmitter has a range of 10Kpa and an accuracy of 0.2% F · S. The transmitter is intended for use with liquids or gases.

Output: 4-20mADC, Power Supply: 24VDC

5.5 vacuum system

The vacuum system is used to evacuate the gas in the diversion chamber and pipeline, ensuring that the test is carried out under the unidirectional flow of the test liquid and ensuring the stability of the test pressure.

The system consists of a 2XZ-2 rotary vane vacuum pump and a vacuum buffer container. The buffer container is made of transparent organic glass, and when saturated water is evacuated, it can be continuously pumped until water appears in the buffer container.

5.6 Backpressure control system

Used to control the outlet pressure of the diversion chamber, the system mainly consists of a top loading back pressure control pressure regulator. When the outlet pressure of the diversion chamber reaches the top control pressure of the pressure relief valve, the pressure relief valve automatically opens to release pressure, ensuring a constant outlet pressure. The control pressure must be controlled by gas to ensure control accuracy, and the control pressure value is displayed by a pressure gauge.

5.7 hydraulic press

Maximum load: 2000KN, maximum distance between pressure plates: 300mm, piston diameter: Φ 250mm, maximum stroke: 50mm, power 0.75KW, power supply: 380Ac 50Hz, loading speed: 3.5MPa/min.

5.8 pressure compensating system

Maintaining the stability of the closing pressure, another function of the compensation pump is to determine the pressure increase by the compensation pump when the closing pressure needs to rise to the upper stage closing pressure.

5.9 Displacement measurement

Suitable measurement range: 0~± 20mm, linearity<0.05%, resolution: 0.01mm

Sensors have strong anti-interference ability against electrostatic induction and electromagnetic fields.

8、 Operation steps

1Blank test of diversion chamber, calibration of empty sample chamber

1.1 Install the upper and lower pistons, sealing rings, and metal plates into the diversion chamber without adding any supporting agent;

1.2 Place the installed guide vane between the two flat plates of the hydraulic press;

1.3 Turn on the oil pump switch and increase the pressure to below * closing pressure. Stop the pump and close the oil pump shut-off valve;

1.4 Use a compensation pump to increase the pressure to * closing pressure and stop the pump;

1.5Measure the distance from the upper pressure plate of the diversion chamber to the upper surface of the diversion chamber with a caliper;

1.6Load the compensating pump sequentially to each closing pressure, and measure the distance from the upper pressure plate of the guide chamber to the upper surface of the guide chamber with a caliper as the basic value for measuring the filling thickness of the supporting agent.

2Preparation of diversion chamber

2.1 Place a stainless steel filter screen at the liquid inlet, outlet, and each pressure tap;

2.2 Place the bottom piston with a sealing ring into the flow chamber;

2.3 Place a metal plate on top of the bottom piston;

2.4 Add a certain amount of proppant into the diversion chamber;

2.5 Use a leveling tool to level the supporting agent used in the experiment;

2.6 Place another metal plate on top of the flattened support agent;

2.7 Will be accompanied by“OPlace the piston of the ring into the guide chamber;

2.8 Place the installed diversion chamber between the two flat plates of the hydraulic press;

2.9 Open the oil pump switch to increase the pressure to a certain level below * closing pressure, stop the pump, and close the oil pump shut-off valve;

3Evacuate saturated water

3.1 Close the valve on the intermediate container, open the pressure measuring hole valve and vacuum pump valve in the diversion chamber;

3.2 Open the vacuum pump to evacuate the flow chamber;

3.3 Take some time to schedule30minLeft and right, open the inlet valve of the middle container, and turn on the horizontal flow pump to inject the test medium into the diversion chamber (pre fill the damper with the test medium);

3.4 Continue to evacuate, and when the test medium is seen flowing out from the vacuum buffer container, turn off the vacuum pump and vacuum valve;

4Test of diversion capacity

4.1Use a compensation pump to increase the pressure to * closing pressure and stop the pump;

4.2 Measure the distance from the upper pressure plate of the diversion chamber to the upper surface of the diversion chamber with a vernier caliper.

4.3 Connect the advection pump, intermediate container, diversion chamber, and pressure measuring pipeline;

4.4 Kaiping flow pump, set the injection flow rate, inject the experimental medium into the flow chamber, and record the flow rate and pressure difference after the differential pressure stabilizes.

4.5 Load the compensating pump sequentially to each closing pressure, and measure the distance from the upper pressure plate of the guide chamber to the upper surface of the guide chamber with a caliper.

4.6 Inject experimental medium into the flow chamber, and record the flow rate and pressure difference under different closing pressures after the pressure difference stabilizes.

4.7 Calculate the permeability and fracture conductivity of proppants using Darcy's formula;

9、 Workflow diagram